LOS ANGELES
— Asquana is a very young mother, yet she's remarkably stoic. Her daughter is about 6 months old, already half her size, and perfectly behaved. But this is no tragic story of teen mothers. Asquana and her daughter, Godzilla, are pet lizards. They're dressed to kill and out to win.

The bad news for them is that first prize in this contest is an eight-pound bag of dog food. The good news is that two of their pet "siblings" are dogs, and they are possibly the lizards' biggest fans at this moment.

This moment is a Halloween pet costume contest at a Petco in the southern Los Angeles neighborhood of Westchester. Asquana and Godzilla are dressed as mother and child, appropriately enough, in costumes that were painstakingly handmade by their human mother, as she is called, Frances Howie.

Godzilla is in a crib, perhaps four inches square, that comes with push-button audio that plays the Brahms' Lullaby, and a baby's voice plaintively saying "maama." Asquana has her hands (OK, her front feet) placed on the rail of the crib and in the world of inscrutable lizard gazes, I believe this would constitute the one of the Madonna. Her lips even appear to have the slight upturn of that mystical smile of Mona Lisa.

I would say they're shoo-in winners. Last year, in fact, Asquana did win – with her own mother. But they face serious competition, the vast majority of which are dogs. Hence the first-place prize.

What these animals represent together is the rapidly growing phenomenon of people dressing up their pets for Halloween.

One website, raisingkids.co.uk, reports that 3.5 million Americans will purchase a Halloween costume for their pet this year. According to Elaine Binner of the eponymous Elaine's Pet Depot in Santa Monica, Calif., that's up from a decade ago by ... well, 3.5 million. "I first saw them [pet costumes] 10 years ago, but I only made sure to stock them in the last four years," she says.

She has been nearly sold out for two weeks, but you can still find a limited selection – ballerina, superhero, and the always popular devil. You can also get your animal to appear as another animal, say a zebra, giraffe, or skunk.

This doesn't appear to cause any identity confusion, and for all we know may have become an inside joke among pets. Picture, if you will, a bunch of pugs in green visors seated at a poker table laughing heartily about what animal they were last Halloween, perhaps under the influence of the dog equivalent of "one too many."

***

Halloween costumes remain a relatively small part of the more than $36 billion spent on pet products each year. Products that, by the way, include pajamas, make-up, and orthodontia. Ms. Binner has several of those costumes. Clancy and Bubba, her Boston terriers, will be dressed as aliens or pumpkins. Her 140-pound Rottweiler will be in a pink tutu. Buddy, her blind Doberman, is exempt from the pageantry.

What do the dogs make of all this? Binner believes "they could not care less." Animal behaviorist Richard Polsky says, "It's enjoyable for the kids and the family, and doesn't change a dog's behavior. So take them out trick-or-treating."

Others are less come-what-may. "Halloween is one of the most dangerous nights of the year for a pet," says Warren Eckstein, an animal behaviorist who may be the "Dr. Phil of pets" – the author of 11 books, including "Pet Aerobics." He says it's OK to put your animal in costume. In fact, Cisco, his Chihuahua, has a leather motorcycle jacket that he wears when Mr. Eckstein gets out his Harley Davidson. "He doesn't ride with me, and it's not real leather," Eckstein is quick to add. "But he has to look macho – he's a little dog with a Napoleonic complex."

But Halloween is different. With all the kids "dressed up as Martha Stewart, or Oprah Winfrey, or worse, it can be very upsetting to animals," he says, suggesting it frightens them. "Don't take your dog out." He also adds that candy – particularly chocolate – can be harmful to animals, particularly dogs.

Yet this Halloween treat crisis can be resolved, I'm here to tell you, if you have a Three Dog Bakery nearby. It's a franchise that sells upscale, freshly baked products for dogs.

There you will find aid from people like Cristina Gonzalez, the pastry chef in the Los Angeles store. She whips out breakfast fare like "pupcakes" and "mutt-aroons" for the regulars, and, this time of year, offers Halloween cookies that she can personalize with your dog's name written in carob.

***

I decide to pay close attention to Asquana and Godzilla, in part because I can't help but wonder if animals who lose costume contests suffer. The two lizards parade around the circle as the master of ceremonies, Charles Holling, calls their names. Mr. Holling is the general manager of the Petco. He understands the agony of defeat. He was in a contest one week earlier that involved "Eatables," food you can eat with your dog. (The humans were not allowed to eat with their hands.) In a race to see who could finish a bowl fastest, Holling came in a close second, behind his boss.

Sure enough, the lizards don't finish in the winner's circle. "They were the most original," the judge later tells me, "but they won last year."

The top prize goes to a Yorkshire terrier named Coco, and her parent/owner Manuel Escobar – both of whom are dressed in Winnie-the-Pooh costumes.

As the animals file out, they seem perfectly oblivious to the results. I don't see a long face on any of them, though it can be hard to tell. For the most part, the humans, predominantly parents and children, are smiling and laughing as well.

Now if you're worried about having missed out on this Halloween, don't. Christmas is right around the corner, and there are still plenty of hot-pink antlers in stock.